Computer Networks .ppt

In this file you can learn and get basic knowledge of Computer networking. Here is highlights the point of networking. and explain the types of computer networking. her easy to understand computer networking.

Easy way to get basic knowledge about networking.

1. Computer Networks
Department: BSCS

2. Computer Networks
Telecommunication
Theexchangeofinformationbetweentwoormanyindividualsiscalled
Communication.ThewordteleisaGreekwordwhichmeansdistance.Hence,
Telecommunicationmeanstheexchangeofinformationbetweentwodistant
places.
ComputerNetwork
Acomputernetworkcanbedefinedasasetofcomputersconnected
togetherforthepurposeofsharingresources.Themostcommonresource
sharedtodayisconnectiontotheInternet.
ApplicationofComputerNetwork
Resource sharing such as printers and storage devices
Exchange of information by means of e-Mails
Information sharing by using Web or Internet
Video conferences, Parallel computing and Instant messaging

3. Personal Area Network (PAN) Local Area Network (LAN)
Metropolitan Area Network (MAN)
Categories of Computer Network

4. APersonalAreaNetwork(PAN)is
smallestnetworkwhichisvery
personaltoauser.
ThismayincludeBluetooth
enableddevices.
PANhasconnectivityrangeupto
10meters.
PANmayincludewireless
computerkeyboard,mouse,
headphonesprintersandTV
remotes.
Personal Area Network (PAN)
Personal Area Network

5. UsuallyLANcoversanorganization‘
offices,schools,collegesoruniversities.
NumberofsystemsconnectedinLAN
mayvaryfromasleastastwotoas
muchas16million.
LANprovidesausefulwayofsharing
theresourcesbetweenendusers.
Theresourcessuchasprinters,file
servers,scanners,andinternetare
easilysharableamongcomputers.
LANsarecomposedofinexpensive
networking.
LANworksunderitsownlocaldomain
andcontrolledcentrally.
Local Area Network (LAN)
Local Area Network

6. Metropolitan Area Network
TheMetropolitanAreaNetwork(MAN)
generallyexpandsthroughoutacitysuch
ascableTVnetwork.
ItcanbeintheformofEthernet,ATM,or
FiberDistributedDataInterface.
MANcanhelpanorganizationtoconnect
allofitsofficesinacity.
BackboneofMANishigh-capacityand
high-speedfiberoptics.
MANworksinbetweenLocalArea
NetworkandWideAreaNetwork.
Metropolitan Area Network (MAN)

7. Wide Area Network
Asthenamesuggests,theWideArea
Network(WAN)coversawideareawhich
mayspanacrossprovincesandevena
wholecountry.
Generally,telecommunicationnetworks
areWideAreaNetwork.
Thesenetworksprovideconnectivityto
MANsandLANs.
Theyareequippedwithveryhighspeed
backbone.
WANsuseveryexpensivenetwork
equipment.

8. Computer Network Topologies

9. Point-to-Point Topology
•Point-to-pointnetworkscontainsexactlytwohostssuchascomputer,
switchesorrouters,serversconnectedbacktobackusingasinglepieceof
cable.
•Thereceivingendofonehostisconnectedtosendingendoftheotherand
vice-versa.
•Ifthehostsareconnectedpoint-to-pointlogically,thenmayhavemultiple
intermediatedevices.
•Theendhostsareunawareofunderlyingnetworkandseeeachotherasif
theyareconnecteddirectly.

10. BUS Topology
•InBustopology,alldevicessharesinglecommunicationlineorcable.
•Alldevicesarelinkedthroughabackbonecable.
•Bustopologymayhaveproblemwhilemultiplehostssendingdataatthesame
time.
•Itisoneofthesimpleformsofnetworkingwhereafailureofadevicedoesnot
affecttheotherdevices.
•Butfailureofthesharedcommunicationlinecanmakeallotherdevicesstop
functioning.
•Bothendsofthesharedchannelhavelineterminator.
•Thedataissentinonlyonedirectionandassoonasitreachestheextremeend,
theterminatorremovesthedatafromtheline.

11. RING Topology
•Inringtopology,eachhostmachineconnectstoexactly
twoothermachines,creatingacircularnetwork
structure.
•Whenonehosttriestocommunicateorsendmessage
toahostwhichisnotadjacenttoit,thedatatravels
throughallintermediatehosts.
•Toconnectonemorehostintheexistingstructure,the
administratormayneedonlyonemoreextracable.
•Failureofanyhostresultsinfailureofthewholering.
•Everyconnectionintheringisapointoffailure.
•Therearemethodswhichemployonemorebackup
ring.

12. STAR Topology
•AllhostsinStartopologyareconnectedtoa
centraldevice,knownashubdevice,usinga
point-to-pointconnection.
•Thatis,thereexistsapointtopointconnection
betweenhostsandhub.
•AsinBustopology,hubactsassinglepointof
failure.Ifhubfails,connectivityofallhoststo
allotherhostsfails.
•Startopologyisnotexpensiveastoconnect
onemorehost,onlyonecableisrequiredand
configurationissimple.

13. Tree Topology
•Also known as Hierarchical Topology, this is the
most common form of network
topology in use presently.
•This topology imitates as extended Star topology
and inherits properties of bus topology.
•This topology divides the network in to multiple
layers of network.
•The lowermost is access-layer where computers
are attached.
•The middle layer is known as distribution layer.
•The highest layer is known as core layer, and is
central point of the network, i.e. root of the tree
from which all nodes fork.
•All neighboring hosts have point-to-point
connection between them.
•If the root goes down, then the entire network
suffers even though it is not the single point of
failure.

14. MESH Topology
•Inthistypeoftopology,ahostisconnected
tooneormultiplehosts.
•Thistopologyhashostsinpoint-to-point
connectionwitheveryotherhostormayalso
havehostswhichareinpoint-to-point
connectiontofewhostsonly.
•Allhostshaveapoint-to-pointconnectionto
everyotherhostinthenetwork.

15. Hybird Topology
•Anetworkstructurewhosedesigncontains
morethanonetopologyissaidtobehybrid
topology.
•Hybridtopologyinheritsmeritsanddemerits
ofalltheincorporatingtopologies.
•Thecombiningtopologiesmaycontain
attributesofStar,RingandBustopology.
•InternetisthebestexampleoflargestHybrid
topology.